There are a variety of jaw designs for workpiece and parts grippers including those with sliding jaw members. Such sliding jaw members are typically positioned in channels that are formed in the base or body of a gripper assembly. The jaws are reciprocally driven back and forth in the channels by fluid actuators or other mechanical means. Such jaw designs are used in gripper assemblies which include two opposable jaws or multiple jaws which are capable of converging on a workpiece or part to be gripped.
An example of a gripping apparatus which includes two slidable opposing jaw members is disclosed in U.S. Pat. No. 4,176,821 and exemplified by the "SHURGRIP" gripper which is available from Phd, Inc., Fort Wayne, Ind. The SHURGRIP gripping apparatus can be provided with optional proximity sensors which sense the position of the gripper jaws. The proximity sensors include switches which are triggered by target structures that are attached to the gripper jaws. The target structures trip switches of the proximity sensors. The tripping of the switches indicates the position of the target structure and hence the position of the jaws
Because different workpieces and parts may require that the jaws of a gripper be positioned at different locations for closing and opening, proximity sensors designed for the SHURGRIP gripper and other slidable gripping assemblies are adjustably positionable. That is, the position of the proximity sensors are adjustable along the axis of travel of the targets.
The present invention is directed to adjustable target assemblies which can be incorporated into slidable jaw members and used in devices such as the SHURGRIP and other devices which include at least one or more slidable gripper jaws. The present invention is further directed to adjustable positioning target assemblies which can be used in conjunction with a variety of positioning devices other than mechanical grippers.